Chemistry p1 doubt

[yasser37]

Hi guys

in June 10 paper 11
question 6
do I take the NH4 and No3 separately or as one unit when calculating?

also can someone explain questions 13 , 22 ,28 , abd 29

[Deadly_king]

Hi guys

in June 10 paper 11
question 6
do I take the NH4 and No3 separately or as one unit when calculating?

also can someone explain questions 13 , 22 ,28 , abd 29

Amonium nitrate exists as NH₄⁺ and NO₃^-. So you should take each of the ions separately.

Jun 10 p11

11. To maintain the concentration of HOCl high, you should impose a change which will cause the equilibrium to shift to the right so that more HOCl is formed at the expense of OCl^-.

Adding a solution of Cl^- or bubbling air through the water will have not effect on the equilibrium.

But adding a solution of OH^-, will increase the latter's concentration. Hence according to La Chatelier's principle, the equilibrium will shift to the left which will in other words decrease concentration of HOCl.

Hence obvious answer is A.

The H+ from the acid will react with OH^- to form water. Hence the concentration of OH- will decrease. In this way the equilibrium will shift to the right forming ore HOCl.

I'll complete the rest asap.

[yasser37]

Thanks m8 but I guess you answered a different question / paper

question 13 asks how does sulfuric acid act

[Deadly_king]

Thanks m8 but I guess you answered a different question / paper

question 13 asks how does sulfuric acid act

Oopz...........sorry dude, i did number 11 instead.

13. Sulfuric acid reacts with sodium chloride to form sodium sulfate and hydrochloric acid. If you determine the oxidation numbers, you'll note that this is not a redox reaction.

Hence you can instantaneously eliminate B, C and D.

Therefore answer is A.

[yasser37]

yes paper 11 question 13 says
How does conc. sulfuric acid act when added to NACL
acid
oxidizing agent
reducing agent
acid and oxidizing agent

also m8 if u can explain in w04 paper 1 Q 10 and 19

[Deadly_king]

yes paper 11 question 13 says
How does conc. sulfuric acid act when added to NACL
acid
oxidizing agent
reducing agent
acid and oxidizing agent

also m8 if u can explain in w04 paper 1 Q 10 and 19

Acid.......see the post before yours.

Nov 04 p1

19. You should write the full equation and then balance it.

(NH4)₂SO₄ + 4O₂ -----> H₂SO₄ + 2HNO₃ + 2H₂O

Answer is D

[Deadly_king]

Jun 10 p1

I think no22 has already been answered.

28. It's because the carbon carrying the bromine atom is also attached to three methyl groups. The latter have a tendency to push the bonding electrons to the carbon carrying an electronegative atom such that it becomes less attracted to nucleophiles like OH^-. This is why the rate of reaction is not affected.

Answer is D

b]29[/b]. I'll proceed by elimination.

Butan-1-ol and 2-methyl-propan-1-ol are first to be rejected since they are primary alcohols.

2-methylpropan-2-ol can form only one type of alkene due to free rotation. The carbon carrying the hydroxyl group is connected to three other methyl group of atoms and should have been able to form 3 alkenes but all of them are identical.

Butan-2-ol should have formed only two types of alkenes but one of them show cis-trans isomerism. Hence it forms 3 types of alkenes.

Hope it helps

[yasser37]

Thanks a lot m8


really helped me there

I appreciate it

[Deadly_king]

Thanks a lot m8


really helped me there

I appreciate it

No problem dude

Just ace the paper tomorrow.

[Dania]

HELP!
The answer is C.

[Deadly_king]

HELP!
The answer is C.

In order to find the bond angles, we should find its structure first.

Let's start with ----> The atom has around it, two bond pairs and two lone pairs of electrons. So it'll have a V-shaped(non-linear or bent) just like in a water molecule. So the bond angle will be 105^o.

Now ----> The atom carries 4 bond pairs of electron which will give rise to a tetrahedral shape. So the bond angle will be 109.5^o.

Last is ----> The atom carries 3 bond pairs of electron but also has one lone pair of electron around it. Therefore it will have a triangular pyramidal shape with bond angle 107^o.

So in order of decreasing bond angles it will be :        

Answer is C.